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GB808031A - Improvements in or relating to superheterodyne radio receivers - Google Patents

Improvements in or relating to superheterodyne radio receivers

Info

Publication number
GB808031A
GB808031A GB2554656A GB2554656A GB808031A GB 808031 A GB808031 A GB 808031A GB 2554656 A GB2554656 A GB 2554656A GB 2554656 A GB2554656 A GB 2554656A GB 808031 A GB808031 A GB 808031A
Authority
GB
United Kingdom
Prior art keywords
circuit
frequency
signal
grid
signals
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB2554656A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
DAVID ALLEN SCOTT DRYBROUGH
General Electric Co PLC
Original Assignee
DAVID ALLEN SCOTT DRYBROUGH
General Electric Co PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by DAVID ALLEN SCOTT DRYBROUGH, General Electric Co PLC filed Critical DAVID ALLEN SCOTT DRYBROUGH
Priority to GB2554656A priority Critical patent/GB808031A/en
Publication of GB808031A publication Critical patent/GB808031A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D7/00—Transference of modulation from one carrier to another, e.g. frequency-changing
    • H03D7/06—Transference of modulation from one carrier to another, e.g. frequency-changing by means of discharge tubes having more than two electrodes
    • H03D7/10—Transference of modulation from one carrier to another, e.g. frequency-changing by means of discharge tubes having more than two electrodes the signals to be mixed being applied between different pairs of electrodes

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Superheterodyne Receivers (AREA)

Abstract

808,031. Radio receivers. GENERAL ELECTRIC CO. Ltd., and DRYBROUGH, D. A. S. Aug. 20, 1957 [Aug. 21, 1956], No. 25546/56. Class 40 (5). The invention relates to superheterodyne radio receivers for receiving amplitude modulated signals in one frequency band and frequency-modulated signals in a higher band. According to the invention the valve used as the frequency changer for the amplitude modulated signals is used as an intermediate frequency amplifier for the frequency-modulated signals, the local oscillation injection grid being screened from the signal grid and being used for automatic gain control when the frequency modulation signals are being received. The circuit shown uses a triode-heptode frequency changer for A.M. signals, the local oscillator circuit 25, 28, 30 being tuned to provide a 470 kc/s. I.F. signal in the tuned output circuit 20. On switching over to F.M. reception a 10.7 Mc/s. I.F. signal derived from a further frequency changer which is brought into circuit by the switch is applied to the signal grid of the valve in place of the A.M. signal. A further contact 29 changes over, causing the local oscillator to be disabled by shunting it with a low-impedance circuit 31, 32 and connects the oscillator injection grid through a filter resistor 38 to a source of A.G.C. voltage derived from the ratio detector 33 of the F.M. channel. A 10.7 Mc/s. I.F. output is derived from a tuned circuit 21, the secondary winding of which is connected in series with the secondary winding of circuit 20 to the grid of a further valve acting as an I.F. amplifier for both signals.
GB2554656A 1956-08-21 1956-08-21 Improvements in or relating to superheterodyne radio receivers Expired GB808031A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB2554656A GB808031A (en) 1956-08-21 1956-08-21 Improvements in or relating to superheterodyne radio receivers

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2554656A GB808031A (en) 1956-08-21 1956-08-21 Improvements in or relating to superheterodyne radio receivers

Publications (1)

Publication Number Publication Date
GB808031A true GB808031A (en) 1959-01-28

Family

ID=10229438

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2554656A Expired GB808031A (en) 1956-08-21 1956-08-21 Improvements in or relating to superheterodyne radio receivers

Country Status (1)

Country Link
GB (1) GB808031A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2173660A (en) * 1985-03-28 1986-10-15 Multitone Electronics Plc Paging receiver

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2173660A (en) * 1985-03-28 1986-10-15 Multitone Electronics Plc Paging receiver

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